Vehicles are capable of performing on-board diagnostics to identify leaks in the fuel system. Some diagnostics tests are performed while the engine is running in order to utilize engine intake vacuum. Some tests may be performed in response to the activation of a cruise control mode, as such a mode indicates that the vehicle will be traveling steadily and for a long enough period of time for the test to complete.
However, initiating a leak test whenever cruise control is enabled may result in false fails and/or a waste of resources, since cruise control may be terminated for a variety of reasons. For example, traffic may suddenly be congested due to an accident and cruise control may be disabled when the vehicle slows down or comes to a stop. As another example, a driver may turn on cruise control for a short period of time before arriving at his or her destination. Upon arrival at the destination, the leak test is terminated when cruise control is disabled or the engine turns off.
The inventor herein has recognized the above issues and has devised various approaches to address them. In one embodiment, a method comprises initiating a leak test via an electronic controller in a vehicle responsive to selected route conditions. In this way, a leak test may run without premature termination, therefore saving resources.
In another embodiment, a method comprises evaluating a projected route responsive to receiving a cruise control signal, and initiating a leak test responsive to selected entry conditions. In this way, a leak test may run based on predicted success of the leak test.
In another embodiment, a method comprises initiating a leak test responsive to receiving a cruise control signal, and modifying adaptive cruise control acceleration limits responsive to initiating the leak test. In this way, a leak test may not be disturbed by automatic acceleration and deceleration of a vehicle.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.